Periodontal repair after reduction o inflammation

The purpose of this study was to clarify the relationship between alveolar bone repair and level of connective tissue attachment after reduction of inflammation in an experimental marginal periodontitis. Perodontitis was induced by tying plaque retentive silk ligatures around the mandibular second and third bicuspids in four squirrel monkeys. Ten weeks later the ligatures were removed. An oral hygiene regime of mechanical claning was started and continued three times a week for ten weeks. Induction of perodontitis around the same teeth of the contralateral side (control) of the jaw was timed so that the interproximal perodontium corresponded to the situation immediately prior to ligature removal. The coronal interproximal perodontium between the bicuspids was histometrically analyzed for level of connective tissue attachment, location of crestal alveolar bone, percentage of infiltrated supracrestal connective tissue. Before reduction of inflammation, apporximately 70% of the supracrestal connective tissue was infiltrated After oral hygiend, the infiltrate was loclized adjacent to the epithlium and occupied 20% of the connective tissue. Although the supracrestal connective tissue became organized, there was no coronal gain of connective tissue attachemnt and long junctional epithlia were present. However, singnificant bone repair occurred which increased bone volume and reduced periodoantal ligament width. Mechanism of bone resorption and reapair in periodontitis are discussed.     

Healing after root reimplantation in the monkey

The aim of the present investigation was to evaluate the regenerative potential of the periodontal tissues following tooth reimplantation using a model which excluded the dentogingival epithelium from the process of healing. Maxillary and mandibular incisors, premolars and molars of 5 monkeys were used. Following root filling of all experimental teeth, the teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted following the elevation of full thickness flaps. The crowns were separated from the roots at the level of the buccal cemento-enamel junction and the roots immediately reimplanted into their sockets. The flaps were replaced and sutured to accomplish complete coverage of the roots. In a 2nd group, the teeth were subjected to the same experimental procedure, but in addition, the buccal alveolar bone was removed to about half its original height prior to root reimplantation. The teeth of the 3rd group were subjected to identical experimental procedures as for group II with the addition that the buccal root surfaces were planed to the level of the surgically created bone crest. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. The results showed that a complete fibrous re-attachment formed onto roots on which the original periodontal ligament tissue was preserved. This occurred irrespective of whether the roots were reimplanted into sockets with normal (group I) or reduced (group II) bone height. When the original periodontal ligament tissue was removed by root planing before reimplantation (group III), healing resulted in a significant amount of new connective tissue attachment. However, coronal to the newly formed fibrous attachment, the root surface frequently showed signs of resorption and particularly so in those roots which remained covered by the soft tissue during the entire course of healing. In the majority of the roots which perforated the covering soft tissue during the early phase of healing, the dentogingival epithelium had migrated apically into contact with the coronally generated fibrous attachment. In these cases, root resorption was never discernible. New bone formation occurred to a variable extent in the roots of groups II-III. No relationship was found, however, between the amount of connective tissue reattachment or new attachment and newly formed alveolar bone, which in turn indicates that bone tissue regrowth and periodontal ligament regeneration are unrelated phenomena.     

Formation of the biologic width following crown lengthening in nonhuman primates

The purpose of this study was to determine if and how the biologic width is reestablished following surgical crown lengthening. Crown-lengthening surgery was performed on the right or left maxillary and mandibular central and lateral incisors of three adult monkeys, with contralateral teeth serving as unoperated controls. Twelve weeks after surgery, tissue blocks were removed for histologic analysis. The results of a histometric evaluation indicate that the biologic width is reestablished following surgical crown lengthening. The junctional epithelium generally migrates to the apical level of root planing. Space for the supracrestal connective tissue fiber groups is created by crestal resorption of alveolar bone.     

Healing following surgical treatment and root demineralization in monkeys with periodontal disease

Abstract The aim of the present investigation was to study the potential for new attachment to root surfaces which 1) had become devoid of attachment either by mechanical removal or in conjunction with experimental periodontal tissue breakdown and 2) subsequently had been conditioned with citric acid. Three adult monkeys (Macaca cynomolgus) were used. Periodontal pockets were produced during a 2–6-month period around the maxillary central incisors and first and second premolars and around the mandibular central incisors by the placement of orthodontic elastics. Surgical treatment of the pockets was carried out with the use of a flap procedure. During surgery, the roots of the premolars on the right side of the jaws were first scaled and planed and subsequently treated with citric acid. Citric acid conditioning was not performed on the premolars of the left side. In the front tooth regions the surgical treatment included citric acid conditioning of the mandibular central incisors in two animals and of the maxillary central incisors in one animal. Surgical procedures were also carried out around the mandibular second premolars and first molars which had not been exposed to periodontal tissue breakdown. Folio wing flap elevation, the buccal bone plate was mechanically removed within an area corresponding to that of bone loss produced by the experimental periodontitis model in the maxillary premolars. The cementum layer of the surgically denuded portion of the roots was removed by root planing. In all treated teeth, a notch was prepared in the buccal root surfaces at the level of the alveolar bone crest. Six months following treatment the animals were sacrificed and histologic sections prepared. Linear measurements were made along the root surface from the apical border of the prepared notch to the apical termination of the junctional epithelium and to the crest of the alveolar bone. The results demonstrated that cementum formation and new connective tissue attachment did not occur on root surfaces previously exposed to periodontal pockets and subsequently subjected to scaling and root planing or on root surfaces surgically deprived of their supporting bone and previously “non-exposed” cementum layer. Cementum formation and new connective tissue attachment also failed to occur following citric acid conditioning of root dentin surfaces. In all sections representing all three treatment groups, the attachment between the gingiva and the root was established by epithelium.     

Trauma and progression of marginal periodontitis in squirrel monkeys

Previous studies have shown that repeated trauma to the interproximal periodontium induced by jiggling of teeth resulted in alveolar bone loss and, when combined with periodontitis, increased the amount of bone loss compared with periodontitis alone. This study was designed to answer the question on the reversibility of such bone loss. Eight squirrel monkeys were divided into two equal groups. In four animals, the mandibular second and third bicuspids were jiggled mesio-distally for ten weeks. On one side a marginal periodontitis was induced at the same time. In the other four animals the same procedures were instituted except these animals were killed ten weeks after jiggling had been stopped. Step-serial histoiogial sections of the coronal interproximal area were analyzed. Loss in height of alveolar bone and percentage of bone occupying the coronal area were measured histometrically. When jiggling was stopped, a significant reversibility of bone loss occurred. However, no such reversal was seen in the presence of periodontitis. It was postulated that presence of an existing marginal inflammation inhibited the potential for bone regeneration.     

Periodontal repair in dogs Healing patterns in large circumferential periodontal defects

This report describes the healing patterns of large circumferential periodontal defects in the beagle dog. Approximately 5 mm large periodontal defects were created around the mandibular premolars (P2, P3 and P4) in 13 animals. The root surfaces were then instrumented to remove all cementum and the wounds immediately closed by replacing and suturing the flaps just coronal to the cemento-enamel junction. Block biopsies were harvested after 4 weeks. Most of the surgically denuded root surface healed with connective tissue repair. Cementum formation and regeneration of alveolar bone was limited and averaged approximately 30% and 20%, respectively, of the defect height. Almost all teeth exhibited root resorption. Ankylosis was observed in 1/3 of the teeth. There was no difference in the healing response between the 3 premolars or their buccal and lingual surfaces. The range of healing responses indicates that a biological potential exists which makes this model useful for testing the effect of various root and wound conditioners in (1) enhancing cementum formation on the root surface, (2) increasing regeneration of alveolar bone and (3) preventing aberrant healing events such as root resorption and ankylosis. Conversely, whether such agents may compromise wound healing and result in reduced connective tissue repair may concomitantly be tested.     

Guided tissue regeneration. An experimental procedure in beagle dogs

This preliminary study examined the healing following an experimental procedure designed to facilitate coronal migration of progenitor cells from the periodontal ligament circumferentially on roots of premolar teeth in beagle dogs. Mucoperiosteal flaps were reflected on the buccal and lingual aspects of premolars in six beagle dogs with periodontal disease. Following root preparation, pieces of orthodontic wire were placed interproximally on the crowns to bridge the spaces between teeth. Biobrane, a synthetic membrane bonded to a knitted nylon fabric and coated with collagen, was placed as a physical barrier between the roots and the flaps to be replaced. The membrane extended as a single piece from the cementoenamel junction (CEJ) to overlap the crest of alveolar bone by 3 to 4 mm on both the buccal and lingual surfaces of the three premolars in each quadrant. The membrane was attached to the crowns at the CEJ with resin. The flaps were replaced and sutured. Postoperative care included plaque control and the membranes were removed after 5 weeks. The dogs were sacrificed to provide observation periods of 8 and 16 weeks after placement of membranes. Histologic examination revealed new connective tissue attachment in the apical part of the 8- and 16-week experimental specimens. Some experimental specimens showed new attachment up to 2.94 mm while others showed a long junctional epithelium (JE). Root resorption was also seen in some specimens. These preliminary findings suggest that placement of physical barriers between root surface and flaps may be beneficial in facilitating coronal migration of progenitor cells from the periodontal ligament.     

The effect of progressive tooth mobility on destructive periodontitis in the dog

Abstract. The aim of the present study was to assess the influence of traumatic forces causing a gradually increasing tooth mobility on an ongoing destructive periodontitis.
The experiments were performed in five dogs fed a diet which permitted dental plaque accumulation. Periodontal breakdown was induced around the mandibular third and fourth premolars (₄P, ₃P and P₃, P₄) by the placement of plaque retention ligatures around the neck of the teeth. After 330 days, when approximally 50 % of the supporting tissues had been lost, mucoperiosteal flaps were raised around the four premolars and notches prepared in the buccal root surfaces at the marginal termination of the alveolar bone. The notches served as landmarks for measurements to be made in histological sections. The flaps were resutured and new plaque retention ligatures placed around the roots of all four teeth.
One week later (Day 0), P₃ and P₄ (test teeth) were subjected to jiggling forces in a bucco-lingual direction with the use of an elevator. The jiggling procedure which had a duration of 30 seconds, was repeated on Days 4, 8, 12 and 16, and was guided in such a way that the tooth mobility gradually increased during the experimental period. The animals were sacrificed on Day 26, and sections of ₄P,₃P and P₃, P₄ were prepared for light microscopic examination.
The results of the study demonstrated that jiggling forces, resulting in a progressive increase of tooth mobility, mediated an enhanced rate of destruction of the supporting apparatus in dogs with an ongoing process of periodontal tissue breakdown.     

Root resorption following periodontal flap procedures in monkeys

The effect of a periodontal flap procedure, that included citric acid root conditioning and closure of the wounds by suturing of coronally elongated flaps, was studied in mandibular premolars and molars in monkeys. Three months in advance, to prepare for this regenerative procedure, every other tooth in the mandibular posterior segments was extracted and the alveolar bone level reduced to a level approximately 5 mm apical to the cemento-enamel junction around the remaining teeth. Histologic observations of biopsies removed 6 months after the regenerative surgery disclosed resorption of the treated root surfaces in the majority of specimens. Citric acid treatment of the root surfaces cannot have been primarily responsible for the resorption, as control surfaces, on which acid was not used, also displayed resorption. Resorption occurred most commonly on surfaces in which the junctional epithelium showed limited apical migration and was located 2 mm or more coronal to the apical extent of root planing.     

Probing pocket depth at mobile/nonmobile teeth

The aim of the present investigation was to study the influence of an increased tooth mobility on the resistance offered by the periodontal tissues to probing. 6 beagle dogs were used. At the start of the experiment, the animals had clean teeth and normal gingival and periodontal conditions. In each dog, a device was installed in the lower left jaw quadrant to expose the third premolar (P3) to jiggling forces which would enhance the mobility of this "test" tooth. The contralateral tooth served as the non-jiggled control. During the 3 months of experimentation, the teeth of the dogs were cleaned on a regular basis. Clinical examinations including tooth mobility measurements were performed on days 0 and 90. After the examination on Day 90, a probe was inserted in the buccal "pocket" of the mesial root of 3P and P3. The probe was retained with composite. Biopsies including the test or control tooth with adjacent buccal periodontal tissues were harvested, fixed and decalcified. Each biopsy was divided in one mesial and one distal portion (root). The distal portion was embedded in Epon, sectioned and stained in PAS and toluidine blue, while the mesial portion, following probe removal was embedded in paraffin, sectioned and stained in hematoxylin-eosin. The sections were exposed to histometric and morphometric measurements. The findings demonstrated that tissue alterations which occur at mobile teeth may reduce the resistance offered by the periodontal tissues to clinical probing. Such alterations include (i) reduced height of the alveolar bone, (ii) reduced amount of collagen, and increased vascularity in the enlarged supracrestal connective tissue.     

Tooth mobility and resolution of experimental periodontitis

Abstract The aim of the present experiment was to study alterations in the mobility of teeth that occurred during resolution of experimentally induced periodontitis lesions in the dog. 5, 1-year-old, beagle dogs were used in the study. The left and right 4th, 3rd, and 2nd mandibular premolars (₄P₄, ₃P₃, ₂P₂) served as experimental teeth. Periodontal tissue breakdown was initiated by placing plaque-collecting cotton-floss ligatures around the neck of the experimental teeth. The ligatures were replaced to the level of the receding gingival margin 1 × every month. On Day 120, the ligatures were removed and debridement was performed. A groove, parallel to the long axis of the mesial root, was prepared in the mesio-buccal surface of the crowns of ₂P and P₂. Guided by the groove and with a probing force of 0.5 N, a probe was inserted into the buccal gingival pocket of the mesial root and was attached to the buccal surface. Biopsies including both the mesial and distal root of ₂P and P₂ and the surrounding hard and soft tissues were harvested. The biopsy procedure was repeated in a similar manner 15 days (i.e. Day 135) and 3 months (i.e. Day 225) after ligature removal in the 4th (₄P₄) and 3rd (₃P₃) premolar regions. After fixation, decalcification and sectioning, the biopsy material was exposed to histometric and morphometric measurements. Assessment of the mobility of the experimental teeth was performed on Days 120, 135 and 225 using the Periotest system. The amount of remaining bone at the experimental teeth was evaluated in radiographs obtained in a standardized manner. The findings of the present experiment disclosed that in dogs allowed to form plaque, the placement of cotton-floss ligatures at the neck of mandibular premolars initiated a process that resulted in (i) the formation of an inflammatory lesion which extended deep into the supracrestal connective tissue; (ii) extensive loss of alveolar bone; (iii) markedly increased tooth mobility. It was also observed that, within a 4-month period the removal of the ligature and, as a consequence, a substantial portion of the subgingival microbiota, reduced the size and the apical extension of the inflammatory lesion in the supracrestal connective tissue. The alterations in the soft supracrestal tissue were accompanied by a marked decrease in the mobility of the experimental teeth and a reduced probing pocket depth. It was suggested that the reduced penetration of the probe was the result of the change in the size and position of the infiltrate as well as of a reduced mobility of the experimental teeth.     

Periodontal response to long-term abuse of the gingival attachment by supracrestal amalgam restorations

The combined length of the supracrestal connective tissue attachment and the junctional epithelium is referred to as the "biologic width". The long-term (1-year) effect of complete violation of the supracrestal connective tissue attachment was examined in beagle dogs. Full thickness periodontal flaps were elevated, exposing the buccal bony crests of the maxillary and mandibular canines of 3 beagle dogs. The roots of the experimental teeth were planed and class V cavities were prepared. The apical border of each cavity was located at the alveolar bone crest. The cavities were restored with amalgam and the flaps were repositioned and sutured. In the control sites, a notch was prepared at the CEJ and the distance between the notch and the bony crest was measured. The dogs were sacrificed 57 weeks after the operation and the experimental and control sites prepared for histologic analysis. Every 5th section was examined and measurements were taken of the amount of gingival and bone recession, the length of the connective tissue and the epithelial attachment. Control sites healed uneventfully. Gingival recession averaged only 0.5 mm; bone loss was minimal and averaged 0.15 mm. The combined length of the supracrestal connective tissue and epithelial attachment measured 4.47 mm. In experimental sites, the gingiva receded 3.16 mm on average. Moderate bone loss (mean = 1.17 mm) was noted, but no signs of bone resorption were seen at the time of sacrifice. After bone loss, root surfaces which were previously attached to alveolar bone by periodontal ligament were mainly (0.90 mm) attached to connective tissue.(ABSTRACT TRUNCATED AT 250 WORDS)     

Connective tissue reattachment as related to presence or absence of alveolar bone

The present study was designed to examine if alveolar bone, located adjacent to a root surface deprived of its periodontal ligament and cementum layer, can stimulate the reformation of a connective tissue attachment. The maxillary and mandibular incisors in 3 monkeys were extracted. Immediately after tooth extraction, the buccal root surfaces of the incisors from the left side of the jaws were planed by means of curettes to a level corresponding to half the root length. All teeth were then reimplanted into their original sockets. However, before tooth reimplantation, the buccal alveolar bone plate was removed in 2 of the monkeys to a level corresponding to half the depth of the sockets. The animals were sacrificed 6 months after the reimplantation procedure. The jaws were removed and histological sections of the experimental teeth and adjacent periodontal tissues were produced. The sections were analyzed in the microscope and subjected to histometric measurements. The results demonstrated that, irrespective of the presence or absence of alveolar bone, a fibrous reattachment failed to form on that part of the reimplanted teeth which had been deprived of their periodontal ligament. This indicates that alveolar bone located adjacent to a root surface may have limited influence on the biological conditions which determine whether periodontal healing results in connective tissue reattachment or new attachment.     

Osseous repair in the presence of active tooth hypermobility

The present investigation was undertaken to evaluate the periodontal response after resolution of inflammation in a situation of established marginal periodontitis, but in the presence of active, continued tooth hypermobility. Periodontitis was induced unilaterally around mandibular second and third bicuspids in 4 squirrel monkeys by tying plaque retentive silk ligatures at the gingival margins. Jiggling trauma to the periodontium between these bicuspids was begun 5 weeks later and continued for the remaining 20 weeks. Ligatures were removed 15 weeks after placement, whereupon regular oral hygiene was begun and continued. Periodontitis and trauma were produced around the corresponding contralateral teeth (control) so that the interproximal area represented the situation immediately prior to ligature removal. Infiltrated connective tissue, loss of connective tissue attachment and alveolar bone, and percentage of bone were determined histometrically for each coronal interproximal periodontium. In control specimens, 58% of the supracrestal tissue was infiltrated with inflammatory cells compared to 19% in experimental specimens. There were no differences in levels of connective tissue attachment or crestal alveolar bone. However, bone repair occurred in the experimental specimens which increased bone volume from 11 to 18% (P less than 0.05). It was concluded that osseous repair occurred in the presence of active, continued tooth hypermobility after resolution of inflammation.     

Submergence of roots for alveolar bone preservation. I. Endodontically treated roots.

Mandibular premolars in four dogs were endodontically treated and then totally submerged. Histologic and radiographic findings showed that this procedure should be considered as an alternative to extraction of key teeth in an effort to preserve alveolar bone. 1. Periodic follow-up on this procedure should be done to rule out cystic formation. 2. Beveling the coronal portion to the buccal is advocated to compensate for the thin buccal plate. 3. The procedure should be done in two steps to allow the root canal sealer to set, or an amalgam should be placed over the pulp canal. 4. New cementum and connective tissue will form over the coronal surface separating the dentin from new bone.     

正畸拔牙矫治病例中出现牙龈折痕的临床研究

目的: 探讨正畸拔牙矫治病例出现牙龈折痕原因,为临床预防牙龈折痕的发生提供依据。方法: 在拔除前磨牙进行固定矫治的错牙合畸形患者中,筛查出发生的牙龈折痕病例87例,选择其中一侧出现牙龈折痕,另一侧未出现的病例65例,将出现牙龈折痕的一侧作为实验侧,未出现牙龈折痕的一侧作为对照侧,通过CBCT测量分析,比较两侧牙槽骨宽度、高度及骨密度的变化与出现牙龈折痕的相关性。结果: 牙龈折痕多发生在下颌,牙周探针牙龈折痕深度下颌均大于上颌。牙龈折痕侧牙槽骨宽度减小、高度降低以及密度减小均明显大于对照组,两组数据统计结果有显著性差(P<0.05)。结论: 正畸拔牙矫治病例中牙龈折痕的出现与牙槽骨宽度、高度及骨密度的变化具有相关性,拔牙间隙关闭过程中牙槽骨吸收,对软组织支持的丧失,可能是出现牙龈折痕的解剖学因素。     

Pattern of bone resorption in vertically fractured, endodontically treated teeth

PURPOSE: To evaluate the clinical pattern of alveolar bone resorption associated with vertically fractured, endodontically treated teeth in correlation to clinical symptoms.Material and Methods: The pattern of bone resorption was evaluated in 66 maxillary premolars, 13 mandibular premolars, and 31 mesial roots of mandibular molars extracted during an 18-month period because of vertical root fractures. Type and duration of symptoms were recorded and correlated to the pattern of bone resorption. RESULTS: A V-shaped pattern osseous defect (dehiscence) was typical (91%) to the buccal plate rather than a U-shaped shallow, rounded, slow grade resorption in the palatal or lingual plate. Fenestration of the buccal plate was observed in 10 patients (9%). A positive correlation between type of symptoms and amount of buccal bone resorption was found (P <.0001). The resorptive defect was always facing the fracture line. CONCLUSIONS: A typical pattern of bone resorption in vertical root fracture cases as shown in this study can be helpful to the clinician in diagnosing vertical root fracture when an exploratory full flap surgical procedure is performed.     

Soft tissue reactions to non-submerged unloaded titanium implants in beagle dogs.

The soft tissue reactions to non-submerged unloaded titanium implants were examined. A total of 24 implants were placed in 6 beagle dogs. The implants differed in their crestal area by having either a rough sandblasted, a fine sandblasted, or a polished surface. After 3 months, all implants were firmly anchored in the bone and had no clinical signs of peri-implant inflammation. Undecalcified histologic sections demonstrated that all implants achieved osseointegration with direct bone contact. The epithelial structures showed a peri-implant sulcus with a non-keratinized sulcular epithelium and a junctional epithelium. None of the sections exhibited epithelial downgrowth to the alveolar crest. In the supracrestal area, a direct connective tissue contact to the implant post was observed. An approximately 50 to 100 microns wide zone of dense circular fibers was found close to the implant surface. It was free of blood vessels and resembled closely an inflammation-free scar tissue formation. This zone was surrounded by a looser connective tissue with a 3-dimensional network of collagen fibers running in different directions. No significant differences concerning soft tissue reactions were found between the 3 implant surfaces. In particular, the length of direct connective tissue contact was similar. Concerning bone reactions, a significantly shorter distance from the top of the implant to the most coronal bone-implant contact was observed for rough surfaces. It is concluded that non-submerged unloaded titanium implants achieved a complication-free tissue integration with a dense connective tissue in direct contact to the implant surface in the supracrestal area, and epithelial structures similar to those around natural teeth. The different surface textures did not influence the healing pattern of the soft tissues, but had an influence on the location of the most coronal bone-implant contact.     

Some periodontal tissue reactions to orthodontic tooth movement in monkeys

The purpose of the experiment reported was to study soft tissue changes at teeth which were orthodontically moved into areas with varying thickness and quality of periodontal tissues. The maxillary central incisors and first premolars in 5 adult monkeys were used as experimental teeth. 6 months prior to the start of the orthodontic treatment phase, the maxillary second premolars were extracted. By surgical means, areas with varying width of the keratinized gingiva were established in the incisor and premolar region. Following a clinical baseline examination which involved assessments of gingival width, location of the gingival margin in relation to cemento-enamel junction and probing attachment level, fixed orthodontic appliances were inserted in order to bodily move the two contral incisors in labial direction through the alveolar bone envelope and the first premolars in distal direction into contact with the first molars. Orthodontic forces were applied for a period of 3-4 months. The lateral incisors and first molars were selected as non-moved control teeth. After the experimental teeth had been retained in their new positions for 1 month, the clinical examination was repeated. Tissue blocks containing test and control specimens were subsequently dissected and prepared for microscopic analysis. The analysis included histometric assessments of loss of connective tissue attachment and height of alveolar bone. The results showed that at every second labially moved incisor, the gingival margin had become displaced in apical direction. The degree of displacement, however, was small and only at 2 teeth accompanied by loss of connective tissue attachment. Throughout the study, these particular teeth also showed obvious signs of gingival inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nonsurgical management of ectopic teeth

Four cases have been presented involving malpositioned premolars and molars that were brought into the arch. From the cases presented, it appears that aggressive surgical intervention to redirect ectopic premolars creates significant secondary problems. Interference with the bone surrounding the ectopic tooth may compromise the adjacent teeth and bone level. Pressure against the root of the impacted tooth may cause resorption. If the buccal or labial plate is removed, orthodontic movement will be impeded. Specific biochemical changes in bone are induced by the application of orthodontic forces. In these cases, creating space with coiled spring appliances resulted in remarkable reorientation and proper eruption of ectopic, impacted teeth. When surgical intervention is required in cases involving ectopic teeth, close collaboration between orthodontist and oral and maxillofacial surgeon is imperative to achieve successful results without negative sequelae.